Metal polisher



D. F. KITZEL METAL POLI SHER Sept. 10, 1968 5 Sheets-Sheet 1 Filed Aug.10, 1965 Sept. 10, 1968 D. F. KlTZEL 3,400,498

METAL POL I SHER Filed Aug. 10, 1965 5 Sheets-Sheet INVENTOR.

5 A 7 TOENEY.

Sept. 10, 1968 D. F. KITZEL 3,400,498

METAL POLISHEB Filed Aug. 10, 1965 3 Sheets-Sheet 5 f I INVENTOR. F2 2!w 23 1 United States Patent 3,400,498 METAL POLISHER Deilburt F. Kitzel,4767 W. 211th St, Cleveland, Ohio 44126 Filed Aug. 10, 1965, Ser. No.478,539 9 Claims. (Cl. 51-212) ABSTRACT OF THE DISCLOSURE The inventionis directed to a polisher particularly adapted for supporting armatureshafts for rotation against the polishing face while the face remains insubstantially fixed position axially of the shaft, and polishing theshaft uniformly along the entire length of the engaged portion of theshaft to precise cylindrical shape free from circumferential grooves andridges.

The polisher is in the form of a hard, compact, but slightly resilientbody composed of a plurality of strands, each comprising a plurality ofunbraided generally parallel wires. The strands are braided together toform a regular repetitive criss-cross pattern, of which the strandsextend predominantly lengthwise of the polishing direction but obliqueto said direction.

The interstices of the body are filled with fine abrasive grit incarrier material which is flowable under polishing pressure.

This invention relates to a metal polisher for polishing metal surfacesto a smooth finish free from objectionable surface irregularities. Morespecifically, the invention relates to a metal polisher for polishingsurfaces of metal articles to vary precise dimension and mirror finish.

For the purposes of illustration, the polisher is described inconnection with the polishing of metal shafts of alternators and thelike, such as commonly used on many of the present day motor vehicles,its use for polishing other types of shafts and other metallic membersbeing readily apparent from the illustrative example.

In connection with such alternator's, difiiculty has been encountered inproducing consistently precise and highly finished bearing surfaces onthe armature shafts which are to operate in rolling engagement withneedle roller bearings. Very slight irregularities or lines on suchsurfaces result in chattering to a degree which is objectionable fromthe standpoint of noise and detrimental to the alternator parts.Irregularities and lines which cannot be detected readily by the usualinspection procedures nevertheless cause such objectionable operationand are usually not discovered until the alternator is assembled andtest operated. If the faulty operation is thus discovered, the onlymanner of correction is to disassemble the alternator, remove thearmature, repolish the shaft, reassemble the parts, and then retest thealternator.

With the present day polishing methods and instruments, suchirregularities and lines are not consistently eliminated or reduced tosuch an extent as to eliminate the chatter and vibration. In the methodscurrently in use, the polishing is done while turning down thecommutators for concentri-city with the shaft. Ordinarily, in turningdown the commutator on such an armature, the armature is supported bythe end portions of its shaft in upwardly open bearings and is rotated.Generally bearing blocks are pressed downwardly onto the shaft by springpressure to prevent the shaft from shifting in its bearings. Thepolishers presently used are carried by, or seated by, the blocksagainst the upwardly exposed bearing surfaces of the shaft.

If the polishers are maintained in a stationary position axially of theshaft, they do not polish with the degree 3,400,498 Patented Sept. 10,1968 of precision desired, but, on the contrary, form lines orrepetitive patterns of irregularities on the shaft. Attempts have beenmade to eliminate these lines and patterns by reciprocating thepolishers axially of the shaft during the shaft rotation. Reciprocatingthe polishers improves the results, but does not reduce theirregularities and lines consistently to a degree rendering theminnocuous to proper alternator operation.

In accordance with the present invention, a polisher is provided whichcan be applied on the shaft under yielding pressure while retained in afixed position axially of the shaft during turning down or polishing ofthe commutator in the manner hereinbefore described, and which, when soapplied, polishes the shaft at the portion engaged by the polisher to aprecisely dimensioned mirror finish free from detectable lines orsurface irregularities which could adversely affect the operation of thealternator. Furthermore, the present polisher produces such precisemirror finishes without any appreciable reduction in shaft diameter.

Any lines or irregularities which might be present on the precisepolished mirror finish are not detectable without substantialmagnification and are innocuous insofar as concerns the cooperation ofthe surfaces with needle roller bearings.

Various specific objects and advantages of the invention will becomeapparent from the following description wherein reference is made to thedrawings, in which.

FIG. 1 is a perspective view of a polisher embodying the principles ofthe present invention;

FIG. 2 is a right end elevation of the polisher illustrated in FIG. 1;

FIG. 3 is an enlarged fragmentary view of the polisher with the braidsexpanded to show a preferred relation of the individual wires andstrands, and the disposition of impregnating polishing material relativethereto;

FIG. 4 is a fragmentary end view of the structure illustrated in FIG. 3;

FIG. 5 is a top plan view of the modified shape of the polisher;

FIG. 6 is a right end elevation of the polisher illustrated in FIG. 5;

FIG. 7 is a top plan view of another modified shape of the polisher;

FIG. 8 is a right end elevation of the polisher illustrated in FIG. 7;

FIG. 9 is a top plan view of the polisher mounted in a suitable toolsupport;

FIG. 10 is a right end elevation of the structure illustrated in FIG. 9;

FIG. 11 is a top plan view of a band of braided material embodying theprinciples of the present invention, and which may be used in the formillustrated or in folded and compacted form;

FIG. 12 is a front elevation of the band illustrated in FIG. 11;

FIGS. 13 and 14 are diagrammatic illustrations of the steps of forming aband of the material, such as illustrated in FIGS. 11 and 12, into acompacted lbody;

FIG. 15 is a perspective view of a tubular form of band used as thestarting material for making a compacted polishing body;

FIGS. 16 through 19 are diagrammatic illustrations of successive stepsin the forming of the polisher from the starting material illustrated inFIG. 15; and

FIGS. 20 and 21 are diagrammatic illustrations showing the manner inwhich a polisher of the present invention may be used for polishing theshaft of the armature of an alternator, such as commonly used onautomobiles.

In accordance with the present invention, the polisher comprises acompact body v1 which is slightly resilient as distinguished from beingextremely rigid and unyielding.

The body is in the form of a block composed of a plurality of strands 2which are braided together. Each strand 2 preferably comprises aplurality of individual wires 3. The wires 3 of each individual strandpreferably are unbraided with respect to each other, and are braidedonly as a unit with respect to the units forming other strands, due tothe braiding of the strands as a whole.

The interstices between the strands and the individual wires of thestrands are impregnated with a very fine abrasive grits or powder and asolid carrier material which is flowable under pressure. Theimpregnation preferably is throughout the entire body, but the polishingface and contiguous strata must be well impregnated.

The polisher may comprise a single layer of strands. However, thepolisher preferably comprises a plurality of layers, each layercomprising braided strands as described. In such instance, the layersare arranged in juxtaposed face to face relation, the strands of eachlayer extending generally parallel to corresponding strands of the otherlayers. In this application, the direction in which the polisher movesrelative to the surface it is polishing is endwise, and the strandsextend generally endwise of the polisher, but somewhat oblique to thelength of the body.

For polishing the surfaces of a shaft, the operating face of theresultant body 1 is indented with an indentation 5 which extendsentirely across the body transversely of the length of the body and,therefore, transversely of the wires 3. Thus when a shaft is resting inthe indentation and rotating, the periphery of the shaft travels in adirection generally endwise of the strands 2; for example, from thebottom to the top of the body 1 in the position illustrated in FIG. 1.

The advantages of having the identation disposed transversely of thedirection of relative travel of the body 1 and periphery of the shaftare extremely pronounced, as distinguished from an identation whichwould extend, for example, in the direction of relative travel, orendwise of the body. The body 1, as shown in FIGS. 1 through 4, isparticularly desirable for the particular polishing operation heretoforedescribed.

The modification illustrated in FIGS. 5 and 6 is a body 6 of the samegeneral type as the body 1, heretofore described, but it is providedwith an indentation 7 at a corner portion.

The indentations 5 and 7 are not the result of cutting away any of themetal of the body, but are the result of bending and deforming thestrands during formation of the associated body.

In many cases it is satisfactory to provide a body, such as indicated at9 in FIGS. 7 and 8, in which an indentation 10 is provided consisting oftwo planar surfaces 10:: and 10b angularly disposed with respect to eachother.

In the modification illustrated in FIGS. 9 and 10, the

body 11 is such as illustrated in FIG. 1 but mounted in r a suitabletool support in the form of a channel 12 in which the body is firmlyseated, the body preferably being formed therein in the channel duringcompaction of the body, as is later described herein. The channel 12 isprovided with a shank 13 which is receivable in a suitable tool holderfor supporting the polisher in operating position.

Several methods may be employed in the manufacture of the polisher. Forexample, as shown in FIG. 11, the polisher may be formed of a singleband 15 comprised of a plurality of strands braided together, eachstrand preferably being composed of a plurality of wires which areunbraided with respect to each other. The band 15, while it is inrelatively loose condition, as distinguished from a tight, firm band,affords ample opportunity for abrasive grits or powder and flowablecarrier material to enter into the interstices between the strands andthen between the individual wires. While in this loose condition, theband is impregnated with abrasive powder or grit and the flowablecarrier material. When so impregnated, the

band is compressed normal to its face to a relatively rigid,self-supporting, but somewhat resilient body. This body may be of anylength desired and of any width. The faces may be planar, curvilinear orof other desired selected configuration.

Instead of a single ply band, the polisher is preferably made up of aplurality of layers of the band material, these layers being juxtaposedin face to face relation and then compressed into final form by theapplication of pressure normal to the faces. For example, as shown inFIG. 13, the single band 15 is shown as folded back and forth uponitself to provide a stack of portions of band material. Of course, ifdesired, the band may be cut into lengths and a number of the cutlengths stacked. The layers or stack of band material, with facesjuxtaposed, are placed in a cavity of suitable die 17 and are compressedby means of a ram or companion die 16 having a bulge 18, to provide anindentation 19, such as above described, in the resultant body. Thismanner of making the polisher is quite satisfactory.

As illustrated in FIGS. 15 through 19, another method is disclosed. Inthis form, the starting material is a tube 20 with strands which arebraided together, each strand comprising a plurality of individualunbraided wires, such as illustrated in FIG. 11. The length of thestrands is generally lengthwise of the tube but oblique to the length ofthe tube. The tube is preferably relatively loosely braided so as toprovide ample interstices for impregnation. The tube first may beflattened, as illustrated in FIG. 16, by rolling, or by the applicationof pressure transversely to its longitudinal axis. When thus collapsedand flattened, it may be folded or bent endwise about an axis extendingtransversely of its length and parallel to its flat faces and the tworesultant portions juxtaposed in face to face relation, as illustratedin FIG. 17. The portions thus juxtaposed then may be wound into a coilabout an axis extending transversely of its length, to a shape such asindicated in FIG. 18. At any time during this procedure, before or.after it is wound into a coil, it is impregnated with the flowablecarrier and the abrasive powder. After impregnation it is placed in acavity of die 21 and, by a companion die 22, is compacted fiatwise or ina direction normal to its flat faces, into a body, such as hereinbeforedescribed.

The impregnation may be carried out in various ways, the use ofhypodermic type needles and the like for pressure injection of theimpregnating material, being preferred. The impregnation is such thatthe material is distributed throughout the entire body.

The wire used for the strands is preferably copper, though other softwire may be used.

The abrasive or powder should be extremely fine, depending on the timeto be used in polishing, the preciseness and degree of finish desired,and the circumferential speed or relative travel speed between thepolisher and the surface to be polished. The particle size preferablyranges from minimum size that can be measured up to 5 microns.

The abrasive preferably is diamond grit, silicon carbide, aluminumoxide, and mixtures of all or part thereof. Other well known abrasivegrits, depending upon the particular type of metal to be polished, maybe used. The diamond is superior, being sharp and retaining itssharpness for long periods of use.

The carrier material is preferably a composition of propylene glycol,stearic acid, castile soap and polymerized ethylene oxide. Other carriermaterial may be used, the important features being that it is solid, butflowable under pressure so that it and the abrasive are fed to thepolishing surface. It preferably has the consistency at room temperatureof hard or chilled butter.

An example of the composition of grit and impregnating material is asfollows:

Grit up to five microns particle size 2%; Polypropylene glycol Stearicacid 28%;

Castile soap and Polymerized ethylene oxide 10%.

It is desirable that the ends of the bands of braided strands besoldered to prevent unraveling. This is done before impregnation. Asmentioned, the strands may be impregnated by the use of a hypodermictype needle so that the material fills the interstices between thevarious wires, strands and layers, thus being distributed throughout theentire body and thereby providing additional material to be fed out asthat at the surface is carried away.

It is preferable that the metallic composition body be the samethroughout, but this is not absolutely essential, except for longerlife. The important feature is that the polishing face he of thebraided, impregnated material as heretofore described.

For reasons not fully understood, it appears that due to the use of thefiowable carrier material with the braided wire, the body resistsloading by particles of metal from the part being polished. Due to theslight resilience of the resultant body, the continual feeding of theabrasive material from the inner portion of the body to the surface iseffected and replaces any surface material that may be rubbed off orcarried away by the surface being polished.

Furthermore, it has been found that with polishers of this character,shafts can be polished precisely to a mirror finish without anyobjectionable lines or patterns of any nature without any noticeablereduction in the diameter of the shaft as the result of the polishingoperation.

Referring to FIGS. 20 and 21, the use of the present polisher forpolishing the shafts of the armature of an alternator Av is illustrated.In such case, the shafts rest in the polishers 23, which may be the sameas body 1 heretofore described, which acts as a lower bearing for theportion of the shaft to be polished. A suitable fixture 24, havingrollers 25, is pressed by a spring 26 firmly and resiliently onto theupwardly exposed surface of the shaft so as to assure its proper contactwith the block 23. The polisher 23 and shaft remain in fixed axialposition during rotation of the shaft.

The relative surface travel of the polisher and the pe ripheral surfaceof the shaft is generally endwise of, but oblique to the strands.

If the polisher is used to polish surfaces by being moved to and frothereon, for example, in hand polishing, the direction of movement ofthe polisher is preferably endwise of the strands.

Having thus described my invention, I claim:

1. A metal polisher comprising a hard and compact, but slightlyresilient, body formed of a plurality of strands braided together in aregular criss-cross pattern to provide a polishing face of which thestrands extend predominantly lengthwise of the body, but oblique to thelength of the body, each strand being a plurality of relatively softwires which are parallel and unbraided with respect to each other, andthe interstices between the strands being impregnated with fine abrasivegrit and a solid carrier material which is flowable under polishingpressures.

2. A structure according to claim 1 wherein the Wires are copper.

Percent Grit of particle size up to 5 microns from the group consistingof diamond, silicon carbide, aluminum oride, and mixtures thereof 2Polypropylene glycol Stearic acid 28 Polymerized ethylene oxide 10 5. Arnetal polisher according to claim 1 wherein the body is composed of aplurality of layers of said strands, the layers being in face to facejuxtaposition and cornpacted in a direction normal to their juxtaposedfaces.

6. The metal polisher according to claim 5 wherein the wires of eachstrand extend from one edge entirely to an opposite edge of the stack.

7. A metal polisher according to claim 1 wherein the body comprises aradially collapsed hollow tube of which the wall is composed of saidbraided strands, the strands extending generally endwise of the tubeoblique to the tube length and having face portions along its lengthdisposed in face to face relation to each other.

8. A metal polisher according to claim 1 wherein the body has anexteriorly exposed polishing portion, the strands of said portion beingbent and distorted so as to provide, in the polishing face of saidportion, an indentation extending transversely of the length of the bodyfor the full width thereof, and of uniform shape throughout said width.

9. A metal polisher according to claim 1 wherein the criss-cross patternof the strands exposed in the polishing face of the body is such thathalf of the strands are oblique to the length of the body at an acuteangle to said length and in a direction from the left edge to the rightedge and the other strands are oblique at an obtuse angle to the lengthof the body in said direction.

References Cited UNITED STATES PATENTS 1,147,279 7/1915 Sweetland15209.5 2,284,738 6/ 1942 Hurst 51400 2,395,068 2/1946 Rimer 15-506 X2,413,551 12/1946 Englund 15506 X 2,983,941 5/1961 Beyer et a1. 15209.53,078,489 2/1963 Miller 15-2095 3,150,470 9/ 1964 Barron 51400 3,175,3313/1965 Klein 51400 2,780,041 2/ 1957 Larsen 51-304 X 2,899,290 8/1959Riegler 51-304 2,980,524 4/1961 Morton 51-304 X LESTER M. SWINGLE,Primary Examiner.

D. G. KELLY, Assistant Examiner.

